Ocular inflammatory diseases, including uveitis, cause significant visual loss. Previous non-human investigations have identified several cell types, receptor systems and metabolic intermediates that have led to treatment approaches for human patients. However,information on the human genetic expression of these steps in defined inflammatory disease states is lacking. This non-intervention study proposes to obtain peripheral blood and tissue specimens from patients enrolled in other intramural trials for ocular inflammatory diseases and to apply contemporary cDNA microarray technologies for the analysis of differential gene expression. Test results will not be reported to participants or used for diagnostic or therapeutic purposes.The study?s primary objective is to identify unique gene expression profiles as well as disease relevant genes for patients with ocular inflammatory disease at defined clinical stages using cDNA microarray analysis. This will help provide further insight to understand the pathological mechanisms and potential targets for treatment. Some 3,000-5,000 genes will be examined starting with a selected set associated with interleukin (IL) proteins and their receptors, and with tumor necrosis factors (TNF). Purified peripheral blood mononuclear cells (or whole blood lysates using RNA isolation procedures) will be used to isolate total RNA from these samples. Samples will be taken during periods of active or recurring inflammatory disease and again during periods of quiescence after treatment. The microarray tools and methods for genetic analysis are now available at the NEI.In conjunction with these studies are functional assays and cell surface markers of negative regulatory cells, so called ?suppressor cells?. These studies center for the moment on the CD25+ T cell fraction and certain markers of T cell activation such as GITR. A correlation is being made between T cell activation and these negative regulatory signals and clinical activity.